Method and apparatus for extracting proteins



y 1951 J. H. OBEY 2,559,257

METHOD AND APPARATUS FOR EXTRACTiNG PROTEINS Filed 0012. 2, 1946 3 Sheets-Shet 2 INVENTOR TTORNEYS.

July 3, 1951 .1. H. OBEY METHOD AND APPARATUS FOR EXTRACTING PROTEINS Filed Oct. 2, '1946 3 Sheets-Sheet 5 7 20 fiJ LT INVENTOR I ATTORN EYS Patented July 3, 1 951 METHOD AND APPARATUS FOR EXTRACTIN G PROTEINS James H. Obey, Pittsburgh, Pa., assignor to J. R.

Short Milling Company, Chicago, 111., a corporation of Illinois Application October 2, 1946, Serial No. 700,685

This invention relates to extraction columns such as are employed for the extraction of soluble matter from comminuted solids.

While applicable to many other purposes, the apparatus has been particularly designed for use in extracting protein from soy bean flakes.

The general object of the invention is to devise apparatus for this purpose which is very simple in construction, and at the same time more practical and efilcient than anything previously known.

In extraction apparatus of this general character, it is customary to employ a vertical column or tower, and to feed the comminuted material in one direction through this tower while the solvent liquid flows in the opposite direction therethrough. Where the material is heavier than the liquid, as is usually the case, it passes downwardly through the tower, while the liquid flows upwardly. This countercurrent arrangement obviously results in the liquid becoming progressively more concentrated as it approaches the top of the tower, where it is discharged, and it is, of course, highly desirable that this progressive increase in concentration should occur.

Also, it has been proposed to cause the cornminuted material, as it travels downwardly in the tower, to take a zig-zag path, for the purpose of slowing the rate of movement of the material and for increasing the length of the path. This has been accomplished by employing a series of screens or foraminous baffies, arranged one below the other, so that the material cascades from one bafile to the next. In order to cause the material to travel freely over these bafiles, it has been proposed to vibrate or reciprocate at least some of them vertically. Such reciprocation, however, if violent or of considerable extent, will agitate the whole body of liquid, thus destroying the above mentioned progressive increase in concentration. Such violent agitation will also tend to disintegrate or break up the material, thus producing fine particles that cannot be removed from the system, and will cause cloudiness in the extract.

A specific object of the present invention is to provide means for reciprocating or vibrating the bafiles in a specific manner, in order to cause the desired movement of the material and obtain the optimum effect, while at the same time avoiding agitation of the body of liquid as a whole, and reducing to a minimum the disintegration of the material. This is accomplished by vibrating the baiiles at relatively high speed and with a relatively small amplitude.

Another specific object is to vibrate the baffies at such speed that they move, during their down stroke, at a speed greater than the rate at which the material will fall by gravity through the liquid. The purpose of this is to dislodge the material from thebafile at each stroke, so that the 7 Claims. (01. 260-1235) position of the particles is constantly changed, and the action of the-solvent liquid thus rendered more effective.

A still further object is-to so arrange the baiiles Y that, for a given size of tower, a path of maximum length is provided for the travel of the comminuted material. To this end, the bafiles are designed to extend substantially the full width of the tower.

Yet another specific object is toso construct apparatus of this character that there are no fixed parts projecting inwardly from the walls of the tower, on which fixed parts the comminuted material may lodge and accumulate. In addition, the absence of fixed parts makes it possible to so construct the baflles and thesupport on which they are mounted, that the entire assembly may be freely withdrawn from the tower at any time, for cleaning or repairs.

With the above andother objects in view, and to improve generally upon the details of such apparatus, the inventionconsists in the construction, arrangement andcombination of parts hereinafter described and claimed and illustrated in the accompanying drawings, forming partof this specification, andin which:

Fig. 1 is a side elevation of my complete apparatus, parts being shown in section;

Fig. 2 is a plan view on an enlarged scale, of the apparatus shownin Fig. 1, parts being broken away and parts shown insection;

Fig. 3 is a fragmentary vertical section on an enlarged scale showing the upper part of the tower illustrated in Fig. 1;

Fig. 4 is an edge elevation of the upper part of the tower showing one' means for vibrating the bailies;

Fig. 5 is a plan view of one of my improved bafiles, the supporting structure being shown in section;

Fig. 6 is a side elevation thereof, including fragments of the supporting structure;

Fig. 7 is an end elevation thereof;

Fig. 8 is a fragmentary side elevation on an enlarged scale showing a portion of the conveyer chain and means for attaching the porous plates; and

Fig. 9 is a transverse section through the-chain on a similar scale, showing one of the porous plates.

Referring to the drawings in detail, my improved apparatus comprises a column in the form of a vertical tank I shown as rectangular in cross section. The bottom of this tower is open and is connected by means of a hopper 2 with the lower end of an elevator of the endless conveyor type. This comprises two-parallel inclinedtubes 3 and 3a, both communicating with said hopper, and having open upper ends.

The upper end of the tower l is enlarged, as

desired, a discharge pipe (not shown), communi V eating with this settling chamber, may be provided for discharging the sediment from time to time. The concentrated solvent liquid, passing through the outer screen 5a, collects in the space between this screen and the enlarged portion 4 of the tower, and a discharge or overflow pipe 6 communicates with this space.

Extending vertically within the tower l is a supporting frame consisting of a pair of parallel rods 1, united at their upper ends, as indicated at 8, and connected with the lower end of a rod 9. This rod is secured at its upper end to an eccentric strap l0 surrounding an eccentric ll fixed to a shaft i2. The other end of this shaft carries a socket l2a, which fits over the end of a second shaft l3, and is secured thereto by means of a set screw [3a, so that the apparatus maybe readily dismantled. The shaft [3 is journalled in a pillow block l4, carried by a suit able support. To the other end of the shaft I3 is secured a pulley l5, which may be driven by means of a belt l6 from any suitable source of power. The exact details of this eccentric and shaft construction are immaterial, and may be varied as desired.

As clearly shown in Figs. 1 and 3, there is secured to the rods 1 a series of foraminous baffles l1, arranged one above the other, and adjacent baflles being reversely inclined. From an inspection of Fig. 3, it will be seen that these baffles are disposed in staggered relation, with one end of each bafile projecting beyond the end of the one immediately above it, into close proximity to the walls of the tower. Thus two adjacent baffles together extend substantially across the interior of the tower from one side to the other, and interpose a resistance to liquid flow which is substantially uniform over the entire cross-sectional area of the tower.

For the best results, at least so far as the handling of soy bean flakes is concerned, I find that the angle of these baffles is very critical, and they should preferably be disposed between 13 and 25 to the horizontal, the exact degree of inclination depending considerably upon the character of the flakes being treated and the rate at which it is desired to have the flakes progress through the tower. V

In Figs. 5, 6 and "I, the details of construction of one of these baffles is shown. It consists of a rectangular metal frame on the sides and one end of which upwardly extending peripheral flanges l3 are formed, while at the other end 20 a flange extends downwardly as shown at 21 Thus, the baflle is in the nature of a'flat pan, closed on the sides and one end, and open at the other end.

Extending transversely of the baffle are a pair of cross bars 22 or supporting brackets, secured to the side members of the bafile frame by means of bolts 23, working through longitudinal slots 24. Each bar 22, midway of its length, is formed with an open sided notch 22a adapted to receive one of the supporting rods 1, this notch being considerably larger than the rod, however, so that substantial clearance is provided between them.

,On each side of each notch internally threaded fixtures 25 are welded or otherwise secured to the under surface of the cross bar 22, and headless set'screws 26 work through these fixtures and engage the sides of the rods 1, as shown in Figs. 5 and 7, to clamp the brackets thereto. The entire baflle frame is covered on its upper sidewith woven wire netting 21, openings, of course, being provided in this netting where it surrounds the rods 1.

As a result of the above described construction, it will be seen that by loosening the screws 26, the baffles may be set at any desired distance apart on the rods 1, and may also be tilted to any desired angle. After they have been adjusted to the desired position, the screws are, of course, tightened, thus clamping the baffle in place. For simplicity of illustration, the baffles have been shown in Figs. 5, 6 and 7, as at right angles to the rods.

Not only are the baffles adjustable relative to the rods I, but the baflie frame is adjustable longitudinally of the cross bars 22, by reason of the slotted connection 24. Thus, by loosening the bolts 23, the bafiles may be shifted laterally of the tower so that their ends can be brought into the proper relation with each other and with the walls of the tower.

In the elevator tubes 3 and 3a works an endless chain 28, carrying porous propelling members or plates 29. As shown in Fig. 8, the chain carries'at suitable intervals blocks 28a, each having a transverse notch 28b in the outer face thereof. Each porous member 29 comprises a rigid frame 23a covered with woven wire netting, and having an inwardly oifset central portion 2% which fits in the notch 28b and is secured in p0- sition by means of pins 280. The shape and size of the frames 29a is, of course, such that they fit loosely within the elevator tubes 3 and 3a. The chain 28 operates over lower and upper sprocket wheels 30 and 3|, the latter being mounted on a shaft 32, which may be driven as by means of a suitable pulley and belt 33, as indicated in Fig. 2.

34 indicates the pipe through which solvent liquid is introduced into the apparatus, and 35 indicates a spout or chute by which the soy bean flakes are fed into the tower. For extracting protein from the soy bean flakes, the particular solvent liquid is water, containing sufficient alkali or other chemicals to produce the desired results.

In operation, solvent liquid is introduced through the pipe 34, from which it passes down the elevator tube 3 and thence up into the tower I, where it overflows through pipe 6 and is discharged for further processing.

The soy bean flakes Or other comminuted material are fed into the open top of the tower through the spout or chute 35, being delivered at a point inside of the screen 5. This material falls upon the uppermost baflle l1, down which it travels by gravity, and is discharged from the end of the first bafile, onto the next baflie, and so on. Thus, the material travels in a direction counter to that in which the solvent liquid is moving. The flow of the material is indicated in Fig. l by the curved arrows, while the movement of the liquid is indicated by the lain straight arrows. The direction of travel of the, conveyeris indicated by feathered arrows. It will be understood that the spent material collects in the hopper 2 and is carried upwardl through tube 3 by the conveyor, while the incoming solvent liquid flows downwardly through this tube. Thus the mat'erial is subjected to a washing action by the countercurrent of fresh liquid, and the solute thoroughly removed. The spent material is finally discharged from the upper end of the tube 3.

In order to control the travel of the material over the baflles, and also to increase the effectiveness of the action of the solvent liquid, the baffles are given a substantiall vertical vibratory movement by means of the eccentric l I. This preferably operates at relatively high speed, such as 500 to 700 R. P. M., giving a vibratory movement of corresponding frequency, while the am.- plitude of the movement is extremely small, preferably between one-thirty second and one-quarter of an inch, an amplitude of one-sixteenth of an inch having been found very effective in practice, when utilizing a high density soy bean oilfree flakes.

As a result of this high frequency vibration of small amplitude, the desired movement is imparted to the material. At the same time, since the disturbance of the liquid is substantially localized at each baflle, the main body of liquid in the tower is not thrown into agitation, as a whole. Thus, the desired progressive increase in concentration of the liquid as it approaches the top of. the tower is not disturbed or destroyed.

Furthermore, the speed of movement of the baffles is such that on their down stroke they travel faster than the particles of solid matter can fall by gravity through the liquid. Thus, at each down stroke, the particles of material are dislodged from the baflle and are re-engaged therewith, on the next up stroke. This results in the particles constantly changing their position as they travel along over the baflles. Thus, a different face of each particle is constantl presented to the relatively moving liquid. In this way, extraction is greatly facilitated since the action tends to disperse an concentrated film of. solvent liquid which might otherwise adhere to the surface of a particle and thus prevent. further extraction. By virtue of each particle vibrating with small amplitude within a relatively quiescent liquid, the concentrated extract that under other circumstances might surround the particle is left behind to diffuse into the main body of liquid.

It will be further observed, by reference to Fig. 1, that the baffles extend substantially the full width of the tower from one side to the other thereof, only space enough for suitable clearance being allowed. In this way, the zig-zag path over which the material travels is of maximum length, since the material traverses practically the full width of the tower while travelling over each baille.

Finally, it will be seen that in m improved arrangement, there are no fixed parts projecting inwardly from the walls'of the tower, and that the supporting frame I, 9, is suspended within the tower from the eccentric. Also, the baflles are carried wholly by this supporting frame and have no connection with anything else. Consequently, the entire frame and bafile assembly can be readil removed from the tower when desired, by withdrawing it upwardly through the open top thereof. The baffles are preferably of such dimension that they can pass freely up through the screen 5, or, if desired, the screen may be first removed.

In order to facilitate withdrawal of the baffle assembly, as described, and referring to Fig. 4, the eccentric shaft [2 may be disconnected from the pulley shaft I3.

In order to illustrate the operation of the invention, the following typical example may be given.

Substantially oil-free soy bean flakes, dried at 230-250 F. after the oil extraction, were fed into the chute 35 at the rate of gms. per minute. A 0.1% sodium hydroxide solution was introduced through the pipe 34 at such a rate as to produce 550 ml. per minute of effluent liquor at 6. The baflies were set at an inclination of 15 to the horizontal and were operated at a stroke of one-sixteenth of an inch at a frequency of 600 cycles per minute. The conveyor speed was 0.3 foot per minute. These conditions resulted in the production of a 6% protein solution containing only about 0.1% of solids capable of being removed by centrifuging. This yield was the equivalent of 65% of the protein available. The waste or spent flakes discharged from the upper end of the conveyor contained 16% solids and could be easily dried.

While I have described the movement of the baflies as substantially vertical, it will be understood that this movement, produced as it is by a rotary eccentric, will not be strictly vertical, but will include a very small lateral motion. This may in some cases be practically negligible, so far as results are concerned, but if, in larger installations, it becomes desirable to produce a movement of the baifies which is purely vertical, then a suitable guide bushing may be placed around the lower part of the rod 3, and the upper part of this rod either made slightly flexible or else provided with a universal joint. Since such modification is thought to be obvious, it is deemed unnecessary to illustrate it in detail.

While I have shown and described my improved apparatus and process as used in the extraction of solid material which has a greater density than the solvent liquid, and consequently moves downwardly through the tower by gravity, it will be understood that the principles of the invention may also be applied to operations in which the material to be extracted is of less density than the solvent liquid, and consequently tends to travel upwardly therethrough. In such a case, the solvent liquid would be fed in at 35, and removed at a point near the pipe 34, but below the pipe 6. The comminuted material would be introduced at the top of the tube 3 and carried downwardly by the conveyor to the bottom of the tower, from which point it would rise to the top of the tower, and a suitable means for removing the material at this point would be provided. In this case, the direction of travel of the conveyor, and also the disposition of the ballles, would be reversed.

In any event, regardess of the relative density of the material and the solvent liquid, it will be understood that the process operates on a countercurrent principle, and that the material and liquid movein opposite directions.

What I claim is:

1. In the operation of an extraction column including a tower filled with liquid capable of dissolving the substance to be extracted, said liquid being of lower specific gravity than the solid material being treated, the steps which comprise feeding the solid comminuted material, containing soluble matter, into the upper end of said tower, so that it moves downwardly by gravity through said liquid, feeding solvent liquid into the bottom of said tower so that it flows upwardly therethrough, whereby the solvent liquid becomes progressively more concentrated as it approaches the top of the tower, and imparting to said material a substantially vertical vibration to increase the effectiveness of the action of the solvent, such vibration being of such small amplitude and such high frequency that it does not substantially agitate the body of liquid as a whole, whereby the desired progressive variation in its concentration is not disturbed.

2. In the operation of an extraction column including a tower filled with liquid capable of dissolving protein from oil-free soy bean material, the steps which comprise feeding the soy bean material to be extracted into the said tower so that it moves through the liquid therein in one direction, feeding solvent liquid into said tower in such manner that it flows therethrough in the opposite direction, whereby the solvent liquid becomes progressively more concentrated as it approaches the end of the tower toward which it flows, and imparting to said material a substantially vertical vibration to increase the effectiveness of the action of the solvent, such vibration being of such small amplitude and such high frequency that it does not substantially agitate the body of liquid as a whole, whereby the desired progressive variation in its concentration is not disturbed.

3. The method of extracting protein from soy beans which comprises preparing the bean material in the form of substantially oil-free flakes,

continuously feeding such flakes into a body of aqueous liquid capable of dissolving protein and of lower specific gravity than said flakes, so that said flakes tend to travel downwardly through said liquid, and imparting to said flakes while immersed in such liquid a substantially vertical vibration at a frequency of at least 500 cycles per minute, with an amplitude of one thirty-second to one-quarter of an inch, whereby each particle moves within a relatively quiescent liquid and the effectiveness of the action of the solvent is increased, and causing said liquid to flow upwardly in a countercurrent past said downwardly moving flakes.

4. An extraction column comprising a vertical tower adapted to contain solvent liquid, 2. single vertically extending rigid supporting frame disposed within said tower, a single shaft mounted above said tower, means on said shaft for suspending and vertically vibrating said frame, a series of foraminous bafiies wholly carried by said frame and disposed one below the other, adjacent baffles being oppositely inclined, and means for feeding the material to be extracted on to the uppermost of said baffles, said material being denser than said liquid whereby it cascades by gravity from one bafile to the next, said tower having an open top and being wholly free from any inwardly projecting fixed parts, whereby said frame and attached baffles may be withdrawn upwardly as a unit from said tower.

'5. In extraction apparatus, the combination with a tower, of a series of foraminous bafiles in said tower, said bafiles being disposed one below the other and inclined alternately in opposite directions, an elevator extending upwardly from the bottom of the tower and comprising a pair of tubes containing the runs of an endless conveyer having porous propelling members fitting said tubes, means for feeding comminuted material to be extracted onto the uppermost of said bafiies, a single vertically extending rigid frame to which said baffles are attached and by which they are wholly supported, means at the upper end of said frame for vertically reciprocating the same, and the baffles attached thereto, so as to cause the material to travel therealong and cascade from one bafile to the next to the bottom of the tower, from whence it is carried upwardly by said elevator, and means for feeding solvent liquid into the upper end of that one of said elevator tubes housing the upwardly moving run of the conveyer, whereby said liquid flows down-- wardly through said upwardly traveling porous propeller members and through the spent com-- minuted material propelled thereby.

6. In a counter-current extractor, a tower having an inlet for material to be treated and an outlet for solvent liquid at one end, an outlet for said material and an inlet for said liquid at the opposite end, a vertically extending rigid frame arranged within but mechanically free from said tower, a zig-zag vertical series of angularly disposed foraminous bafiles rigidly attached to and carried wholly by said frame, said baffles being, and disposed in staggered relation, with one end of each bafile projecting beyond the end of the baffle immediately above it, into close proximity to the walls of the tower, whereby a pair of adjacent baflles together extend substantially across the interior of the tower, and means for vertically vibrating said frame.

7. In an extraction apparatus, the combination with a tower, of a frame extending vertically therein and comprising a pair of rigidly connected parallel rods, baffle supports mounted on said rods, foraminous baflles carried by said supports, independent means for releasably clamping each of said bafile supports rigidly to each of said rods, said means being constructed and arranged to permit adjustment of the vertical distance between said baffles and the angu-" lar position of each baflle, and means for vertically reciprocating said rigid frame.

JAMES H. OBEY.

, REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 35,701 Palmar et al. Jan. 24, 1862 86,192 Walker Jan. 26, 1869 518,102 Haag Apr. 10, 1894 605,772 Barthelemy June 14, 1898 693,455 Stanley Feb. 18, 1902 1,328,819 Carter Jan. 27, 1920 1,511,238 Singer Oct. 14, 1924 2,150,608 Olier Mar. 14, 1939 2,260,640 Rawling et a1. Oct. 28, 1941 2,271,620 Brier et a1. Feb. 3, 1942 2,276,298 Frazier Mar. 17, 1942 2,297,685 Brier et al. Oct. 6, 1942 FOREIGN PATENTS Number Country I Date 426,472 Great Britain Apr. 1, 1935 

2. IN THE OPERATION OF AN EXTRACTION COLUMN INCLUDING A TOWER FILLED WITH LIQUID CAPABLE OF DISSOLVING PROTEIN FROM OIL-FREE SOY BEAN MATERIAL, THE STEPS WHICH COMPRISES FEEDING THE SOY BEAN MATERIAL TO BE EXTRACTED INTO THE SAID TOWER SO THAT IT MOVES THROUGH THE LIQUID THEREIN IN ONE DIRECTION, FEEDING SOLVENT LIQUID INTO SAID TOWER IN SUCH MANNER THAT IT FLOWS THERETHROUGH IN THE OPPOSITE DIRECTION, WHEREBY THE SOLVENT LIQUID BECOMES PROGRESSIVELY MORE CONCENTRATED AS IT APPROACHES THE END OF THE TOWER WHICH IT FLOWS, AND IMPARTING TO SAID MATERIAL A SUBSTANTIALLY VERTICAL VIBRATION TO INCREASE THE EFFECTIVENESS OF THE ACTION OF THE SOLVENT, SUCH VIBRATION BEING OF SUCH SMALL AMPLITUDE AND SUCH HIGH FREQUENCY THAT IT DOES NOT SUBSTANTIALLY AGITATE THE BODY OF LIQUID AS A WHOLE, WHEREBY THE DESIRED PROGRESS VARIATION IN ITS CONCENTRATION IS NOT DISTRUBED. 